There is a big variety of different storage devices that is offered in the market today. In particular, there is a high degree of diversity in the field of portable and semi-portable storage devices. A few examples of such devices are hard disc drives, flash memory devices, memory card reader/drive devices, optical disc (drives), etc. It is desirable that these devices work flawlessly with as many different data processing systems as possible so that the user is flexible in terms of the utilisation of the storage devices.
Many of these storage devices use a universal serial bus to interface with other devices and data processing systems respectively. The advantage of using a universal serial bus is its high level of standardisation and proliferation in today's market. However, some storage devices use other interfaces, for example SD-card-devices. Because of the multitude of different storage devices and connection means, there is a large difference in characteristics between the storage devices that exist today. For example, one of the main problems for car manufacturers is to assure a reliable operation of portable and semi-portable storage devices with the data reproduction system or data processing system of a car. These systems comprise, for instance, car audio systems, navigation systems, and the like. Because in the past car data reproduction systems have shown many interoperability issues with storage devices, car manufactures were reluctant to add USB-connectivity or the like to cars. As a result, many data reproduction systems of cars do not allow for the addition of external storage devices.
Methods and devices known from the prior art that have tried to address this issue have exclusively concentrated on controlling the transmission bandwidth required for the transmission of data from the storage device to the data reproduction system. Examples for such methods and systems are disclosed in U.S. Pat. No. 6,295,516 B1, EP 1 638 257 A1 and U.S. Pat. No. 6,658,512 B1.
However, testing on part of the applicant has shown that the storage devices still do not always reliably work with data reproduction systems, even if the bandwidth requirements are met. Especially with audio systems for cars testing has shown that audio playback didn't always reliably work with USB-storage devices, even if the bandwidth was sufficient. The reason for this is that the characteristics of USB-devices vary in a very wide range depending on the use they are optimized for.